This invention relates to a new and improved shortening composition. In particular, it relates to a pourable solid shortening wherein the solids content index is a minimum of 15% at 110.degree. F. and a maximum of 78% at 92.degree. F. as denoted by area CGH on FIG. 1. The composition is processed into a form sufficiently thermodynamically stable to resist melting and agglomeration at elevated storage temperatures, yet retains excellent cooking qualities. The preparation of such shortenings requires the specific selection of starting materials, processing conditions, and particle size and shape.
Practically all pourable solid frying fats which have been produced previously in powdered, flaked, or particle form have a tendency, particularly after storage at room temperature for a short time, to become sticky and to form lumps which are not easily broken apart. The powder particles or flakes agglomerate to form larger lumps or a solid mass. This tendency is increased by exposure to high storage temperatures, and can result in the melting of particulate fats suitable for cooking. Refrigerated storage can be employed to help prevent agglomeration and melting, but is not always practical. These problems of agglomeration upon storage have been countered primarily by three means: (1) encapsulation or enrobing; (2) use of high-melting fat materials; and (3) tempering processes.
Encapsulation or enrobing provides a protective coating around a low melting material. Often a higher melting fat is used as the encapsulating material, thereby containing any melting of the encapsulated material. Thus, agglomeration or caking of the product upon prolonged storage is decreased. The encapsulation technique has been successfully applied for a viriety of protective purposes such as prevention of moisture absorption, delay of reaction of active components, prevention of elution of a specific entity until heated to a minimum temperature, etc. However, encapsulation to avoid agglomeration of fat particles at common storage temperatures is not always adequate. It has been necessary to use anti-caking agents in some cases in combination with encapsulation to increase the effectiveness of the technique. See U.S. Pat. Nos. 3,754,961 issued to Ueno et al on Aug. 28, 1973, and 3,388,997 issued to Schaible et al on June 18, 1968. U.S. Pat. No. 4,343,826 issued to McNaught on Aug. 10, 1982 discloses a process for preparing beaded fats wherein a coating is not deemed necessary, but the packed beads are transferred promptly to a cooled area for storage at 40.degree. to 50.degree. F. to avoid clumping.
A second approach to storage agglomeration problems of particuate fats is simply the use of high melting fatty materials and/or flow conditioning agents. The selection of fats that are highly hydrogenated (low iodine values), and therefore have high-melting point ranges aids in the prevention of agglomeration, but highly hydrogenated fats are not suitable for all shortening uses. Flow conditioning or anti-caking agents are also commonly employed with the high-melting materials. However, such additives may also render the shortening unsuitable for a particular desired end use by adversely affecting factors such as baking, smoking or foaming properties of the shortenings.
A final means utilized to help prevent storage agglomeration problems has been to employ tempering processes to convert fat crystals to their more stable polymorphic phase prior to storage and thereby avoid the evolution of heat of crystal transformation during storage. It is known that crystallizable fatty materials exhibit polymorphic crystal behavior, i.e., they can exist in different distinct crystalline forms known as alpha, alpha-prime, beta, beta-prime, etc., arising from different patterns of molecular packing in the crystal. Background information in the polymorphic phase structure of edible fats can be found in U.S. Pat. Nos. 2,521,242 and 2,521,243 issued Sept. 5, 1950 to Mitchell; Ferguson and Lutton, Chem. Rev. 29, 355 (1941); Lutton, J. Am. Chem. Soc., 67, 524 (1945); and Lutton, J. Am. Oil. Chem. Soc., 27, 276 (1950). The crystal form obtained is dependent upon the temperature and speed at which crystallization is permitted to take place. The least stable crystalline forms, alpha and beta prime, tend to form upon rapid chilling of a molten fat. Transformation of these lower melting alpha and beta-prime crystals to the more thermodynamically stable beta form can occur over extended periods of time. Crystal transformation is accompanied by evolution of heat.
The prior art (see U.S. Pat. No. 3,973,053 issued to Galusky et al on Aug. 3, 1976) discloses a process for quick tempering of solid fat powders by agitating the particulate fat in a gas fluidized bed at 50.degree. F. to 80.degree. F. The cooling gas absorbs the heat of crystal transformation of the particulates. Also known is a method for manufacturing fat powders by spray drying wherein the fat is first held within a specific temperature range, i.e. between the congeal point and the melting point of the fat, to promote beta crystal formation prior to the spraying process, and then held at 32.degree. F. to 50.degree. F. for a period after spray drying (see U.S. Pat. No. 3,892,880 issued to Grolitsch on July 1, 1975). The powders are said to retain flowability after long storage at room temperature. The problems encountered in storage at elevated temperatures were not addressed.
Shortening compositions with high melting point ranges having a solid fat content high enough to retain particle integrity at high storage temperatures are believed to impart a waxy or greasy taste to food cooked therein. A solid coating is formed on the food as it cools to below the high melting point range of a substantial percentage of the fats in the shortening. For this reason, shortening compositions with lower melting point ranges, particularly those available in liquid or solid block form, have been extensively used for cooking. A composition which has both a high melting point range to prevent agglomeration on storge and a low melting point range at food eating temperatures to help prevent a greasy taste perception on food cooked therein is highly desirable. Such a product is provided by the present invention.
The shortening compositions of the present invention are advantageous in minimizing the solid coating of shortening formed on food as it cools, as compared to that formed on food cooked in a highly hydrogenated fat, i.e. fats with a solids content index greater than 78% at 92.degree. F. This is especially important with regard to the presence of a greasy or waxy taste perception since many fried foods, such as chicken, are often eaten after cooling. The appearance of the cooled food is also improved because of the reduced development of a waxy coating. Thus, leftover fried food or fried food eaten after it has cooled retains its initial appealing appearance and organoleptic qualities when cooked in the shortening compositions of the present invention.
Currently available solid block cooking shortenings present handling problems when used in large volumes such as in restaurant or institutional cooking. Due to its pourable form, the shortening composition of the present invention promotes safety, improves convenience, and eliminates waste. When used in large volumes uneven packing of solid shortening into electric kettles can cause isolated hot spots to occur in the electric coils which may lead to a flash fire. This is commonly avoided by premelting solid blocks of shortening and transferring the hot liquid shortening into the desired cooking vessel. Upon adding the shortening composition of the present invention to the cooking vessel, it distributes evenly thoughout the kettle. The possibility of flash fires is greatly decreased, thus increasing safety. Eliminating the need to premelt solid shortening and transport the hot liquid further improves safety.
Due to its pourable form the shortening composition of the present invention improves convenience by eliminating the need to remove solid shortening from bulk containers by scooping and dipping. It provides the convenience of a liquid but without the disadvantages of liquid products such as messy containers and spilling. Currently available solid shortenings often stick to their container necessitating time consuming effort to obtain complete removal. Likewise, complete removal of liquid shortenings from their containers entails a draining period, and often requires slight heating of the container to decrease the viscosity of the liquid. The shortening composition of the present invention pours quickly and conveniently from its container with no residue left behind. Time-consuming effort and product waste are avoided. These advantages translate into lower costs for the consumer while still providing high quality food.
Accordingly, it is an object of this invention to provide a pourable solid shortening which is storage stable at elevated temperatures and yet suitable for cooking.
Another object of this invention is to provide a shortening of good organoleptic quality in solid pourable form.
Another object of this invention is to provide a solid shortening that is safer for use in large volumes.
Another object of this invention is to provide a shortening that is more convenient to use and can be easily used without waste.
Another object of this invention is to provide a solid shortening in pourable form with a thermodynamically stable solid fat content to avoid significant agglomeration at storage temperatures up to 110.degree. F., but which when used in cooking provides excellent organoleptic quality of food prepared with it. The food does not have a waxy or greasy taste perception.
These and other objects will become apparent from the following description and examples. All percents are by weight unless otherwise specified.